1. Field of the Invention
The present invention relates to an apparatus for inspecting and maintaining cranes, and more particularly relates to a detachable apparatus for inspecting and maintaining dockside container cranes and other large cranes.
2. Discussion of the Relevant Art
Dockside container cranes and other large cranes frequently require maintenance and repair. Typical maintenance includes painting, mechanical repair and lubrication, due principally to wear and exposure to the weather. Many areas of the crane structure are inaccessible to repairmen due to the height of the crane and the infeasibility of providing safe walkways to access all portions of the structure.
Several devices have been designed to assist in giving repairmen access to the crane structure, such as that disclosed in U.S. Pat. No. 4,676,339, to Rybka, et al and disclosed in U.S. Pat. No. 4,546,852 to Martin et al. Both of these devices use the crane's lifting mechanism to lift a base unit containing extendable manlift platforms which can be extended into proximity of the area of the crane requiring service. The known devices employ large, unwieldy, and costly base units on which the articulated elements of the device are installed. These base units are difficult to store because of their size; are costly, since they must be fabricated for this special application; and are unwieldy, because of the combined weight of the base together with the articulated elements.